[asac][almanews] ALMA Memos 437 Released

[Stacy Oliver]

ALMA MEMO #437

Miniature, Modular Heat Sinks for ALMA Cryostats

D. Koller, J. Effland, A. R. Kerr, K. Crady and F. Johnson (NRAO)

2002/12/02

Keywords:  miniature heat sink, cryogenic electronics, thermal
measurements

Proposed receiver cartridges for ALMA may utilize up to 96 wires for SIS
mixer bias, IF amplifier bias, thermometry and other functions [1].  To
reduce heating of the mixer block and minimize the load on the 4 K
refrigerator stage, heat sinks will be required on the 80 K, 12 K and 4
K stages.  The present concept for the receiver cartridges requires
disassembly of each thermal stage to effect repairs.  Heat sinks
utilizing connectors simplify disassembly, thus improving the mean time
to repair.  The large number of wires and connections will require a
simple, reliable heat sink capable of being mass-produced for the
expected 64 receiver cartridges.

The main body of this report describes two different heat sink designs
utilizing Nanonics "Dualobe" connectors configured in a modular
arrangement for simple installation in receiver cryostats.  In Appendix
B, a simpler but less effective heat sink is described.  The measured
thermal performance of all the heat sinks is presented.

View a pdf version of ALMA Memo #437.
http://alma.aoc.nrao.edu/memos/html-memos/alma437/memo437.pdf

Download a postscript version of ALMA Memo #437.
http://alma.aoc.nrao.edu/memos/html-memos/alma437/memo437.ps
_______________________________________________
Almanews mailing list
Almanews at listmgr.cv.nrao.edu
http://listmgr.cv.nrao.edu/mailman/listinfo/almanews